Wireless power transfer device and wireless charging system having same

• US 9,660,486 B2
• Filed: 05/14/2013
• Issued: 05/23/2017
• Est. Priority Date: 05/14/2012
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Jaesung, Lee, Seonghun, Park, Yongcheol, Kwak, Bongsik, Seo, Jeongkyo, Lee, Hyunbeom
• Primary Examiner(s): Dinh, Paul
• Application Number:
  US14/400,265
• Publication Number:
  US 20150137746A1
• Time in Patent Office: 1,470 Days
• Field of Search: 320108
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00036 Charger exchanging data with battery
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries

Abstract

The present specification provides a wireless power transfer device formed to transmit power to a wireless power reception device, and a power transfer unit in the wireless power transfer device comprises: a first coil formed to generate a magnetic field so as to transmit power in an induction scheme; and a second coil wound around the first coil and formed to generate a magnetic field vibrating at a resonance frequency so as to transmit power in a resonance scheme.

Claims

1. A wireless power transmitter configured to wirelessly transmit power to a wireless power receiver, the wireless power transmitter comprising:

a first coil configured to generate a first magnetic field for transmitting power via inductive coupling to the wireless power receiver;

a second coil wound around the first coil and configured to generate a second magnetic field vibrating at a resonant frequency for transmitting power via resonant inductive coupling to the wireless power receiver; and

a controller configured to;

cause transmission of a detection signal comprising a wireless power signal;

determine a wireless power transmission protocol corresponding to inductive coupling or resonant inductive coupling based on a control message response to the detection signal received from the wireless power receiver; and

cause power to be selectively applied to the first coil or the second coil according to the control message response from the wireless power receiver.

2. The wireless power transmitter of claim 1, wherein a Q value of the second coil is in the range of 100 to 200.

3. The wireless power transmitter of claim 1, wherein a ratio of an edge impedance real number part to a central impedance real number part of the second coil is greater than 1.2.

4. The wireless power transmitter of claim 3, wherein a ratio of an edge impedance imaginary number part to a central impedance imaginary number part of the second coil is smaller than 1.

5. The wireless power transmitter of claim 1, wherein the second coil is formed in a flat spiral structure, and an interval of the second coil is non-uniform.

6. The wireless power transmitter of claim 5, wherein the interval of the second coil gradually becomes more narrow from an inner circumference toward an outer circumference of the second coil.

7. The wireless power transmitter of claim 5, wherein the second coil is formed in a shape in which a single wire of a litz wire or a copper wire is wound from an inner circumference to an outer circumference.

8. The wireless power transmitter of claim 1, wherein the first coil is wound into a circular shape, and the second coil is wound into a quadrilateral shape at least part of which is linear.

9. The wireless power transmitter of claim 1, wherein a signal transmitted from the wireless power receiver is detected via a first unidirectional communication protocol when the power is transmitted via inductive coupling.

10. The wireless power transmitter of claim 1, wherein communication with the wireless power receiver is executed via a bidirectional communication protocol using a channel, other than a power channel, when the power is transmitted via resonant inductive coupling.

11. The wireless power transmitter of claim 10, wherein the wireless power transmitter assigns a timeslot and provides an access ID to the wireless power receiver according to the bidirectional communication protocol.

12. The wireless power transmitter of claim 11, wherein the timeslot comprises:

an access timeslot in which the wireless power receiver generates an individual access ID in response to power applied thereto and transmits the generated access ID to the wireless power transmitter; and

an assigned timeslot in which a plurality of wireless power receivers sequentially transmit responses based on assigned IDs applied from the wireless power transmitter.

13. The wireless power transmitter of claim 10, wherein according to the bidirectional communication protocol:

the wireless power receiver transmits a response to a request of the wireless power transmitter;

or

the wireless power receiver omits the request and transmits a response in an assigned timeslot.

14. A wireless charging system comprising:

a transmitter configured to transmit power wirelessly and comprising a first coil configured to transmit power via inductive coupling and a second coil configured to transmit power via resonant inductive coupling; and

a receiver configured to wirelessly receive power from the transmitter,

wherein the transmitter is configured to;

transmit a detection signal comprising a wireless power signal;

determine a wireless power transmission protocol between inductive coupling or resonant inductive coupling based on a control message response to the detection signal received from the receiver; and

selectively apply power to the first coil or the second coil according to the control message response received from the receiver.

15. The system of claim 14, wherein the receiver transmits a list of supported communication protocols to the transmitter, and the transmitter transmits to the receiver one or more supported communication protocols of the list which are supported by the transmitter.

16. The system of claim 14, wherein:

a signal transmitted from the receiver is detected via a first unidirectional communication protocol when the power is transmitted via inductive coupling, and

communication with the wireless power receiver is executed via a bidirectional communication protocol using a non-power channel when the power is transmitted via resonant inductive coupling.

17. The system of claim 16, wherein the transmitter assigns a timeslot and provides an access ID to the receiver in the bidirectional communication protocol.

18. The system of claim 14, wherein a Q value of the second coil is in the range of 100 to 200.

19. The system of claim 14, wherein the second coil is formed in a flat spiral structure, and an interval of the second coil is non-uniform.